The avenue leading up to the Vatican was filled with 35,000 flowers donated by the Netherlands.

'Boldly negotiate'

"Help us to overcome the scourge of hunger, aggravated by conflicts and by the immense wastefulness for which we are often responsible," Pope Francis prayed.

He appealed for more medical attention for those suffering from the deadly Ebola virus in west Africa and also prayed for the protection of the most vulnerable members of society.

He asked God to "enlighten and inspire the initiatives that promote peace in Ukraine so that all those involved... will make every effort to prevent violence and, in a spirit of unity and dialogue, chart a path for the country's future".

"We pray in a particular way for Syria," he said, expressing the hope that the "defenceless civil population" will be protected from the violence and get the aid they need.

In reference to Syria, he urged the international community to "boldly negotiate the peace long awaited and long overdue".

His message came as Syria's President Bashar al-Assad marked Easter by visiting the ancient Christian town of Maalula.

State television said President Assad inspected a monastery damaged in the fighting that enabled his troops to recapture the town from the rebels.